Oil and gas wells frequently produce a mixed stream of gas, liquid hydrocarbons and water. The mixed stream flows or is pumped to the surface and separated using conventional separating systems. After recovery of the oil and/or gas, the produced water often is reinjected into a disposal well or otherwise recycled or disposed of.
Concerns over possible contamination of the water supply through the presence of oil and other contaminants in the produced water has risen dramatically in recent years. The produced water may contain contaminants such as, for example, difficult to remove aromatics such as benzene, xylene, toluene, phenols and polyphenols. Many governmental authorities require such contaminants to be removed from the produced water before reinjection into a disposal well or other disposition. The level of contamination permitted by government regulation varies. In some older wells recovered oil may be 10% or less of a well's total output and produced water 90% or higher, making it particularly difficult to remove these contaminants from the produced water.
What is needed is a simple economical method for removing contaminants form the produced water.